Compartmentation: Cells and Tissues Flashcards
What are the three major anatomical compartments?
Cranial cavity, thoracic cavity and abdominopelvic cavity.
What is the role of biological membranes?
Separate one compartment from another.
What do biological membranes consist of?
Double layer (bilayer) of phospholipids with protein molecules inserted in them. Small amount of carbohydrates.
What are the 4 functions of the cell membrane?
- Physical isolation
- Regulation of exchange with the environment
- Communication between the cell and its environment
- Structural support
What is the relationship between metabolic activity of a membrane and its protein content?
The more metabolically active the membrane is the more protein it contains.
What are the three types of lipids found in the membrane?
- Phospholipids (major lipid)
- Sphingolipids (lipid rafts)
- Cholesterol (increases viscosity, alters permeability).
What are amphipathic phospholipids?
They have a hydrophilic head and hydrophobic tail.
What are micelles and what are they important for?
They are droplets of phospholipids in a half sphere shape. Important for lipid digestion.
How are liposomes different from micelles?
They have an aqueous center.
What makes up the structure of cell membrane lipids?
Phosphate group head, glycerol back bone, and two fatty acid chains for the tail.
What makes up the fluid mosaic model of the cell membrane?
Proteins dispersed throughout the membrane and the extracellular surface contains glycoproteins and glycolipids.
How are proteins bound to the membrane?
Can be loosely or tightly.
How many different types of proteins can be inserted into the membrane?
10-50 different types.
What are the two types of integral proteins?
Transmembrane and lipid anchored proteins.
What are peripheral proteins?
They attach to integral proteins.
What are the roles of peripheral proteins?
- Participate in intracellular signaling
2. Form submembranous cytoskeleton
What are the roles of integral proteins?
- Membrane receptors
- Cell adhesion molecules
- Trasmembrane movement
- Enzymes
- Mediators of intracellular signaling
How are lipid anchored proteins linked to phospholipids?
Sugar phosphate chain links them to the fatty acids of the phospholipid.
What are lipid anchored proteins commonly associated with?
Sphingolipids instead of phospholipids.
What do lipid rats contain?
An abundance of proteins important in cell signal transduction.
What are the two types of cell membrane carbohydrates and where are they found on the membrane?
Glycoproteins and glycolipids. They are always extracellular.
What are glycoproteins?
A protein with a carbohydrate attached.
What are glycolipids?
A lipid with a carbohydrate attached.
What are the functions of glycoproteins?
Structural, transport and immunologic molecules, hormones, enzymes, and cell-cell recognition.
What is the function of glycolipids?
They serve as recognition sites for cell to cell interactions.
What is cholesterols function in the membrane and where is it positioned?
Positioned between phospholipid tails to add flexibility and help to make the membrane impermeable to small water-soluble molecules.
